Method of restricting access, for the benefit of authorised users, to resources belonging to interactive services with at least one package of services

ABSTRACT

The subject of the invention concerns a process to restrict, to the benefit of authorized users, access to at least one restricted access resource belonging to at least one interactive service of at least one cluster of services, each user having a processing and memorizing unit linked up to a client machine capable of executing a client program adapted to exchange from a transmission network, data with a server program associated to each interactive service having a service identifier, access to a resource being provided by a request sent by the client program to the server program which processes said request and returns to the client program the response to the request.

[0001] The subject of the invention concerns the domain of technical means adapted to restrict access to resources belonging to interactive services being part of at least one cluster of services.

[0002] The subject of the invention finds a particularly advantageous application in the domain of restricted access to resources belonging to interactive services. As non-limiting example, can be considered interactive services such as the consultation of bank accounts, the consultation of legal and/or commercial information on corporations, the consultation of horoscopes, interactive online games, etc. Said interactive services comprise restricted access resources. For instance, for a service relative to the consultation of bank accounts, a restricted access resource is the display of a bank account which is accessible only to the holder of the account.

[0003] To illustrate the subject of the invention, FIG. 1 shows the example of an installation 1 enabling users to access interactive services being part of at least a group or cluster. The installation 1 includes for each user, a client machine 2 enabling to execute a client program adapted to exchange, from a transmission network 3, data with a server program associated to each interactive service. In a simplified manner, each server program of an interactive service is executed by a server machine linked up to the transmission network 3. As non-limiting example, each client machine 2 can be a personal computer, the client program can be a software program of the Internet browser type, the transmission network 3 can be the Internet or an Intranet, the server program can be a web server, and the server machine can be a server of the data processing type.

[0004] In the rest of the description, the interactive services shall be referred to as services identifiers S_(i), (with i varying from 1 to I), the clusters shall be referred to as clusters identifiers B_(j), (with varying from 1 to J), and the server machines shall be referred to as machines identifiers M_(k), (with k varying from 1 to K).

[0005] In the illustrated example, interactive services having as services identifiers S₁, S₂, S₃ and S₄, are accessible respectively from server machines having as machines identifiers M₁, M₂, M₃ and M₃. Moreover, the interactive service having as service identifier S₁ is part of the cluster having as cluster identifier B₁, the interactive service having as service identifier S₂ is part of the cluster having as cluster identifier B₂, the interactive service having as service identifier S₃ is part of the cluster having as cluster identifier B₁ and the interactive service having as service identifier S₄ is part of the two clusters having as clusters identifiers B₁ and B₂. In other words, each user wishing to access one of the interactive services having as services identifiers S₁, S₂, S₃ or S₄ belonging respectively to the cluster(s) having as clusters identifiers B₁, B₂, B₁, B₁ and B₂, must submit a request respectively to the server machine having as machine identifier M₁, M₂, M₃ or M₃.

[0006] For certain applications, the need appears to restrict to the benefit of authorized users, access to interactive services or at least to certain resources of said services. Thus, an interactive service supplier can make at least certain resources of its interactive service accessible to the benefit of users having received an authorization or an access right. Such authorization can be granted to a user in return, for instance, for a subscription to the service, free or in return for payment.

[0007] To fulfill the need expressed above, it appears necessary to authenticate in a reliable manner, a user who has sent a request of access to a restricted access resource of a service and to authorize access to said resource only if the user has an authorization.

[0008] The subject of the invention aims at fulfilling that authentication need by proposing a process to enable access to restricted access resources of interactive services belonging to at least one cluster, only to the benefit of authorized users.

[0009] So as to reach such a goal, the subject of the invention concerns a process to restrict, to the benefit of authorized users, access to at least one resource belonging to at least one interactive service of at least one cluster of services, each user having a client machine capable of executing a client program adapted to exchange from a transmission network, data with a server program associated to each interactive service which has a service identifier, access to a resource being provided by a request sent by the client program to the server program which processes said request and returns to the client program the response to the request.

[0010] The process according to the invention includes the following steps:

[0011] for each cluster, putting at the disposal of each user, a processing and memorizing unit designed to be linked up to the client machine of the user when he wishes to access at least one restricted access resource, the processing and memorizing unit including:

[0012] a cluster identifier enabling to determine the cluster to which the processing and memorizing unit belongs,

[0013] a processing and memorizing unit identifier enabling to characterize the processing and memorizing unit put at the user's disposal,

[0014] and a decryption key enabling the decrypting of information coming from a service of the cluster,

[0015] enabling each client program, to read in the processing and memorizing unit which is linked up to it:

[0016] the cluster identifier,

[0017] and the processing and memorizing unit identifier,

[0018] sending by each server program for a service, at least once to any client program which has submitted a request to it for said service, a list of clusters identifiers enabling to determine to which cluster(s) belongs the service to which the request was submitted,

[0019] memorizing by each client program which receives a list of clusters identifiers in response to a request for a service which has a service identifier, a relation between each cluster identifier and the identifier of the concerned service,

[0020] determining, at the time of the sending of a request to a service which has a service identifier, if the client program has memorized at least one relation between a cluster identifier and the identifier of the concerned service, and in the case where:

[0021] a cluster identifier is found, comparing said cluster identifier with the cluster identifier coming from the processing and memorizing unit and if they are equal, adding to the request sent by the client program, the processing and memorizing unit identifier,

[0022] when a server program receives a request for a service containing a processing and memorizing unit identifier and which requests to access a restricted access resource, determining by using at least the identifier of the concerned service and the processing and memorizing unit identifier, if the user who owns the processing and memorizing unit is entitled to access said resource, and if the user:

[0023] is not entitled to access the resource, returning to the client program by the server program, a response corresponding to a refused access,

[0024] is entitled to access the resource:

[0025] determining using at least the processing and memorizing unit identifier, the encryption key corresponding to the decryption key contained in the processing and memorizing unit linked up to the client machine of the user who has sent the request,

[0026] encrypting by the server program, at least in part, the response to the request of access to the restricted access resource using the encryption key, so as to obtain an encrypted response,

[0027] and returning to the client program by the server program, said encrypted response,

[0028] and when a client program receives an encrypted response:

[0029] decrypting the encrypted response received by the client program using the decryption key contained in the processing and memorizing unit linked up to it,

[0030] and presenting the user with the response to his request, as if said request had reached him non encrypted.

[0031] Another subject of the invention aims at satisfying that authentication need by proposing a process enabling access to restricted access resources being part of interactive services belonging to at least two clusters.

[0032] So as to reach such a goal, the process according to the invention comprises:

[0033] determining, at the time of the sending of a request to a service, if the client program has memorized at least one relation between a cluster identifier and the identifier of the concerned service, and in the case where:

[0034] several clusters identifiers are found, comparing said clusters identifiers with the cluster identifier coming from the processing and memorizing unit and if an equality is found, adding the cluster identifier to the request sent by the client program and already containing the processing and memorizing unit identifier,

[0035] when a server program receives a request for a service containing a processing and memorizing unit identifier and a cluster identifier and which requests to access a restricted access resource, determining by using at least the cluster identifier, the identifier of the concerned service and the processing and memorizing unit identifier if the user who owns the processing and memorizing unit is entitled to access said resource, and if the user:

[0036] is not entitled to access the resource, returning to the client program by the server program, a response corresponding to a refused access,

[0037] is entitled to access the resource:

[0038] determining using at least the cluster identifier and the processing and memorizing unit identifier, the encryption key corresponding to the decryption key contained in the processing and memorizing unit linked up to the client machine of the user who has sent the request,

[0039] encrypting by the server program, at least in part, the response to the request of access to the restricted access resource using the encryption key, so as to obtain an encrypted response,

[0040] and returning to the client program by the server program, said encrypted response.

[0041] Another subject of the invention aims at proposing a processing and memorizing unit including at least:

[0042] a cluster identifier enabling to determine the cluster to which belongs the processing and memorizing unit,

[0043] a processing and memorizing unit identifier enabling to characterize the processing and memorizing unit put at the user's disposal,

[0044] and a decryption key enabling the decrypting of information coming from a service of the cluster.

[0045] Another subject of the invention aims at proposing a client machine of the computer type including means to execute a client program implementing the steps of the process in accordance with the invention.

[0046] Another subject of the invention aims at proposing a server machine of the data processing type including means to execute a server program implementing the steps of the process in accordance with the invention.

[0047] Another subject of the invention aims at proposing a client program to access at least one restricted access resource belonging to at least one interactive service, including means programmed to carry out the steps of the process in accordance with the invention, when said client program is executed on a client machine.

[0048] Another subject of the invention aims at proposing a server program for interactive service including means programmed to carry out the steps of the process in accordance with the invention, when said server program is executed on a server machine.

[0049] Various other characteristics emerge from the description made below in reference to the appended diagrams which show, as non-limiting examples, embodiments and implementations of the subject of the invention.

[0050]FIG. 2 shows a client machine enabling to implement the process according to the invention.

[0051]FIG. 3 shows the sequence of data exchange between the client program of the user and the server program of the service in the case where the process according to the invention enables access to a service belonging to a cluster.

[0052]FIG. 4 shows the sequence of data exchange between the client program of the user and the server program of the service in the case where the process according to the invention enables access to a service belonging simultaneously to several clusters of services.

[0053] The subject of the invention concerns a process enabling authorized users, to access at least one restricted access resource belonging to at least one interactive service. For the implementation of the process according to the invention, each user has, as illustrated in FIG. 2, a client machine 20 enabling to execute a client program to access interactive services as explained in FIG. 1.

[0054] In accordance with the invention, said client program must include additional functionalities compared to a classical client access program.

[0055] As additional functionality, the client program must be able to exchange data with a processing and memorizing unit 30. The processing and memorizing unit 30 includes transfer means and processing and memorizing means. It must be considered that the transfer means are of software and/or hardware nature and are capable of providing and optimizing the data communication between the client machine 20 and the processing and memorizing unit 30.

[0056] Said processing and memorizing unit 30 is able to:

[0057] using the transfer means:

[0058] accept data provided by the client machine 20,

[0059] and return data to the client machine 20,

[0060] using the processing and memorizing means:

[0061] to store data possibly in secret and to retain at least a part of said data even when the processing and memorizing unit 30 is switched off,

[0062] and to carry out algorithmic processing on data, part or all of said processing being possibly secret.

[0063] As non-limiting example, said processing and memorizing unit 30 can be constituted by a material key on the USB bus of the client machine 20 or, preferably, by a chip card 31 and its interface 32 commonly called card reader linked up to the client machine 20.

[0064] In the case where the processing and memorizing unit 30 is constituted by a chip card 31 and its interface 32, the transfer means are split into two parts, one being on the interface 32 and the other one being on the chip card 31. In this embodiment, the absence of the chip card 31 is considered as equivalent to the absence of the processing and memorizing unit 30, inasmuch as the processing and memorizing means contained in the chip card 31 are missing.

[0065] The process according to the invention comprises putting at the disposal of each user, for each cluster having as cluster identifier B_(j), a processing and memorizing unit 30 enabling to access the restricted access resources of the interactive service(s) having as service identifier S_(i) being part of the cluster. In the case where a user wishes to access two clusters of services, as illustrated in FIG. 1, said user must have a first processing and memorizing unit to access the interactive services of the cluster having as cluster identifier B₁ and a second processing and memorizing unit to access the interactive services of the cluster having as cluster identifier B₂.

[0066] Each processing and memorizing unit 30 includes:

[0067] a cluster identifier BU enabling to determine the cluster to which the processing and memorizing unit 30 belongs,

[0068] a processing and memorizing unit identifier UTM enabling to characterize the processing and memorizing unit 30 put at the user's disposal. Classically, said processing and memorizing unit identifier UTM corresponds, for instance to an identification number of the processing and memorizing unit 30,

[0069] and a decryption key KD enabling the decrypting of information coming from an interactive service of the cluster.

[0070] As additional functionality, the client program must be able to exchange additional identification data with server machines.

[0071] As additional functionality, the client program which receives a list of cluster identifiers in the response to one of its requests, must be able to memorize relations between the identifier of the service to which the request was submitted and each of the clusters identifiers of the list.

[0072] As additional functionality, the client program must be able to decrypt, with the help of the processing and memorizing unit 30, encrypted data coming from the server machines.

[0073] For the implementation of the process according to the invention, each server program serving an interactive service executed by a server machine includes additional functionalities compared to a classical server program which does not implement the process according to the invention.

[0074] As additional functionality, each server program for a service has a list of clusters identifiers BS_(j) enabling to determine to which cluster(s) the interactive service belongs. When a request is submitted to the service, the server program for said service sends within the response, said list of clusters identifiers. In the case of FIG. 1, for instance the interactive service having as identifier S₁ returns the list {B₁} and the interactive service having as identifier S₄ returns the list {B₁, B₂}.

[0075] As additional functionality, each server program of an interactive service executed on a server machine determines if a user who has a processing and memorizing unit having as processing and memorizing unit identifier UTM, is entitled to access a restricted access resource. Thus, the server program authorizes or refuses access to said restricted access resource and if access is authorized, encrypts at least in part the response to the request.

[0076] The following description in relation to FIG. 3 makes explicit the process according to the invention enabling a user to access an interactive service belonging to only one cluster at a time. In the illustrated example, it is considered that the user wishes to access the interactive service having as service identifier S₁ belonging to the cluster having as cluster identifier B₁.

[0077] A user wishing to access a resource belonging to an interactive service having as service identifier S₁, must have a processing and memorizing unit 30 corresponding to the access to said service, i.e. a processing and memorizing unit associated to the cluster having as cluster identifier B₁.

[0078] When the processing and memorizing unit 30 is linked up to the client machine 20, the corresponding client program reads in the processing and memorizing unit which is linked up to it:

[0079] the cluster identifier BU. In the considered example, BU is equal to B₁,

[0080] and the processing and memorizing identifier UTM. In the considered example, UTM is equal to 123.

[0081] The client program submits to the server program for the service having as service identifier S₁, a first request RQ₁. Inasmuch as the client program does not know yet whether the server program belongs to a cluster or not, the request sent is a standard request identical to the one sent by a standard client program.

[0082] The server program for the service, having received the access request RQ₁, sends at least once within the response RP₁ to the client program which has submitted the request RQ₁ to it, the list of clusters identifiers BS_(j). In the considered example, the list is constituted by only one element and is therefore represented by {B₁}.

[0083] The client program which receives the response RP₁ containing at least one list of clusters identifiers BS_(j), memorizes a relation between the service identifier S₁ corresponding to the service to which the request RQ₁ has been submitted and each cluster identifier BS_(j). In the illustrated example, the list has only one element and the client program memorizes one relation between the service identifier S₁ and the cluster identifier B₁.

[0084] When the user wishes to access again the interactive service having as service identifier S_(i), the client program prepares a second access request RQ₂. At the time of the establishing of said second access request RQ₂, the client program determines if it has memorized at least one relation between the concerned service identifier S_(i) and a cluster identifier BS_(j).

[0085] In the case where no relation is found, the client program sends a request similar to the request RQ₁. In the case where a cluster identifier BS_(j) is found, the client program compares said cluster identifier BS_(j) with the cluster identifier BU coming from the processing and memorizing unit. If there is no equality between the cluster identifier BS_(j) and the cluster identifier BU, the client program sends a request similar to the request RQ₁. If the cluster identifier BS_(j) and the cluster identifier BU are equal, the client program adds to its request RQ₂, the processing and memorizing unit identifier UTM.

[0086] In the illustrated example, at the time of the sending of the request RQ₂ to the interactive service having as service identifier S₁, the client program detects that it has memorized a relation between S₁ and B₁, so much so that it compares B₁ with the cluster identifier BU coming from its processing and memorizing unit. Since the processing and memorizing unit also contains the cluster identifier B₁, the client program adds to its request RQ₂, the processing and memorizing unit identifier UTM which, in the example, is equal to 123.

[0087] When the server program receives a request RQ₂ containing a processing and memorizing unit identifier UTM and corresponding to a request of access to a restricted access resource, the server program determines whether or not the user owning the processing and memorizing unit is entitled to access the restricted access resource. The server program determines that authorization by using at least the service identifier S_(i) corresponding to the requested service and the processing and memorizing unit identifier UTM. So as to do so, the server program consults, for instance, a database including for the considered service the list of the processing and memorizing unit identifiers UTM authorized to access the requested restricted access resource.

[0088] In the case where the server program concludes that the user is not entitled to access the restricted access resource, the server program sends to the client program a response RP₂ corresponding to a refused access.

[0089] In the case where the server program concludes that the user is entitled to access the restricted access resource, is carried out the determination of an encryption key KE corresponding to the decryption key KD contained in the processing and memorizing unit having as processing and memorizing unit identifier UTM. Said encryption key KE is determined using at least the processing and memorizing unit identifier UTM.

[0090] The server program then encrypts at least in part, the response to the request of access to the restricted access resource by using the encryption key KE, so as to obtain an encrypted response RP₂. The server program then returns to the client program, said encrypted response RP₂. It must be understood that when the server program encrypts, at least in part, a response, said server program generally encrypts preferentially, at least in part, the content of said response.

[0091] In the illustrated example, the server program detects in the request RQ₂, the presence of a processing and memorizing unit identifier namely UTM=123. As it happens that the request RQ₂ corresponds to a request of access to a restricted access resource, the server program determines using at least the service identifier S₁ and the processing and memorizing unit identifier 123, that access is authorized. The server program then determines the encryption key KE using at least the processing and memorizing unit identifier 123. For instance, the encryption key KE is equal to 45678. The server program encrypts using said key KE, at least in part the response to the request of access RQ₂.

[0092] When the client program receives the encrypted response RP₂, the client program decrypts said encrypted response with the help of the decryption key KD contained in the processing and memorizing unit which is linked up to it. The client program then presents the user with the response to his request as if it had reached him non encrypted.

[0093] In the example described in FIG. 3, the process according to the invention enables a user to access an interactive service belonging to only one cluster at a time. FIG. 4 makes explicit the process according to the invention enabling a user to access an interactive service belonging simultaneously to several clusters of services. In the illustrated example, it is considered that the user wishes to access the interactive service having as service identifier S₄, being part of two clusters having as clusters identifiers B₁ and B₂.

[0094] A user wishing to access a resource belonging to the interactive service having as service identifier S₄, must have for at least one of the clusters B₁ or B₂, a processing and memorizing unit 30 enabling to access that cluster. In the example of FIG. 4, it is supposed that the user has at least one processing and memorizing unit associated to the cluster having as cluster identifier B₂. (The description would be similar if the user had a processing and memorizing unit associated to the cluster having as cluster identifier B₁.)

[0095] When the processing and memorizing unit 30 is linked up to the client machine 20, the corresponding client program reads in the processing and memorizing unit which is linked up to it:

[0096] the cluster identifier BU. In the considered example, BU is equal to B₂,

[0097] and the processing and memorizing unit identifier UTM. In the considered example, UTM is equal to 234.

[0098] After the sending by the client program of a first request RQ₁ for the interactive service having as service identifier S₄ to the server program for said service, said server program for the service having received the request of access RQ₁, sends at least once within the response RP₁, to the client program which has submitted the request RQ₁ to it, the list of clusters identifiers BS_(j). In the considered example, the list is constituted by two elements and is therefore represented by {B₁, B₂}.

[0099] The client program which receives the response RP₁ containing at least one list of clusters identifiers BS_(j), memorizes a relation between the service identifier S_(i) corresponding to the service to which the request RQ₁ has been submitted and each cluster identifier BS_(j). In the considered example, the list has two elements and the client program memorizes, on the one hand, a relation between the service identifier S₄ and the cluster identifier B₁ and, on the other hand, a relation between the service identifier S₄ and the cluster identifier B₂.

[0100] When the user wishes to access again the interactive service having as service identifier S_(i), the client program prepares a second access request RQ₂. At the time of the establishing of said second access request RQ₂, the client program determines if it has memorized at least one relation between the concerned service identifier S_(i) and a cluster identifier BS_(j).

[0101] In the case where no relation is found, the client program sends a request similar to the request RQ₁. In the case where one or several clusters identifiers BS_(j) are found, the client program compares said cluster(s) identifier(s) BS_(j) with the cluster identifier BU coming from the processing and memorizing unit. If there is no equality between the cluster(s) identifier(s) BS_(j) and the cluster identifier BU, the client program sends a request similar to the request RQ₁. If equality is found between a cluster identifier BS_(j) and the cluster identifier BU, the client program adds to its request RQ₂, the processing and memorizing unit identifier UTM and the cluster identifier BU.

[0102] In the illustrated example, at the time of the sending of the request RQ₂ to the interactive service having as service identifier S₄, the client program detects that it has memorized a relation between S₄ and B₁ and a relation between S₄ and B₂. The client program then compares the cluster identifier BU coming from its processing and memorizing unit, respectively with the clusters identifiers B₁ and B₂. Since the processing and memorizing unit linked up to the client machine contains the cluster identifier B₂, the client program adds to its request RQ₂, the processing and memorizing unit identifier UTM and the cluster identifier BU, which, in the example, are respectively equal to 234 and B₂.

[0103] When the server program receives a request RQ₂ containing a processing and memorizing unit identifier UTM and a cluster identifier BU, and corresponding to a request of access to a restricted access resource, the server program determines whether or not the user owning the processing and memorizing unit is entitled to access the restricted access resource. The server program determines that authorization by using at least the cluster identifier BU, the service identifier S_(i) corresponding to the requested service and the processing and memorizing unit identifier UTM.

[0104] In the case where the server program concludes that the user is not entitled to access the restricted access resource, the server program sends to the client program a response RP₂ corresponding to the refused access.

[0105] In the case where the server program concludes that the user is entitled to access the restricted access resource, is carried out the determination of an encryption key KE corresponding to the decryption key KD contained in the processing and memorizing unit having as processing and memorizing unit identifier UTM and as cluster identifier BU. Said encryption key KE is determined using at least the cluster identifier BU and the processing and memorizing unit identifier UTM.

[0106] The server program then encrypts, at least in part, the response to the request of access to the restricted access resource by using the encryption key KE, so as to obtain an encrypted response RP₂. The server program then returns to the client program said encrypted response RP₂.

[0107] In the illustrated example, the server program detects in the request RQ₂, on the one hand, the presence of a processing and memorizing unit identifier UTM, namely UTM=234 and, on the other hand, a cluster identifier BU, namely B₂. As it happens that the request RQ₂ corresponds to a request of access to a restricted access resource, the server program determines that access is authorized using at least the service identifier S₄, the cluster identifier B₂ and the processing and memorizing unit identifier 234. The server program then determines the encryption key KE using at least the cluster identifier B₂ and the processing and memorizing unit identifier 234. For instance, the encryption key KE is equal to 56789. The server program encrypts using said key KE, at least in part the response to the request of access RQ₂.

[0108] As explained in relation to FIG. 3, when the client program receives the encrypted response RP₂, the client program decrypts said encrypted response with the help of the decryption key KD contained in the processing and memorizing unit which is linked up to it. The client program then presents the user with the response to his request as if it had reached him non encrypted.

[0109] As it emerges from the previous description, the process according to the invention enables to authenticate in a simple and reliable manner, thanks to the implementation of processing and memorizing units, a user wishing to access restricted access resources of interactive services belonging to one or several clusters of services.

[0110] According to a characteristic of implementation of the invention, the process can enable to link up simultaneously several processing and memorizing units 30 ₁, with 1 varying from 1 to L, to the client machine 20 of a user. According to that variant embodiment, the process according to the invention is modified in the following manner.

[0111] The client program is adapted to read, in each of the processing and memorizing units which are linked up to it:

[0112] the cluster identifier BU₁,

[0113] and the processing and memorizing unit identifier UTM₁.

[0114] When the client program sends a request to a service having as service identifier S_(i), the client program determines if it has memorized at least one relation between the concerned service identifier S_(i) and a cluster identifier BS_(j). In the case where a cluster identifier BS_(j) is found, the client program compares said cluster identifier BS_(j) with the clusters identifiers BU₁ coming from the processing and memorizing units.

[0115] If equality is found, the client program adds to the sent request, the processing and memorizing unit identifier UTM₁ having checked the equality.

[0116] When the client program sends a request to a service having as service identifier S_(i) and for which it has memorized at least two clusters identifiers BS_(j), the client program compares the clusters identifiers BS_(j) with the clusters identifiers BU₁ coming from the processing and memorizing units.

[0117] If a least one equality is found, the client program:

[0118] chooses one of the processing and memorizing units having checked an equality,

[0119] and adds to the request sent by the client program, the chosen processing and memorizing unit identifier UTM₁ and the corresponding cluster identifier BU₁.

[0120] When the client program receives an encrypted response, the client program must find the processing and memorizing unit whose identifier UTM₁ has been transmitted during the request corresponding to said response. The three following preferred implementations are possible:

[0121] the client program memorizes the processing and memorizing unit identifier which is transmitted during a request and is able to find said identifier during the response,

[0122] the server program returns to the client program within the response, the processing and memorizing unit identifier UTM₁ received in the request, thus enabling the client program to find said identifier,

[0123] the client program questions each of the processing and memorizing units, so as to find the processing and memorizing unit to use.

[0124] When the processing and memorizing unit is found, the client program decrypts the encrypted response using the decryption key KD₁ contained in the processing and memorizing unit thus found.

[0125] In the previous description, the process aims at determining whether or not the user is entitled to access a restricted access resource. It must be considered that said determination can be carried out:

[0126] either only through the server program,

[0127] or through the server program helped by a remote auxiliary program.

[0128] Said remote auxiliary program can run on a machine distinct from the server machine for a service. According to a preferred embodiment, it can be planned to gather together on a same machine the remote auxiliary programs of all the services of a cluster, so as to centralize the access rights management.

[0129] In the previous description, the process consists in determining the encryption key KE. Note that the determination of said encryption key KE can be carried out:

[0130] either only through the server program,

[0131] or through a server program helped by a remote auxiliary program.

[0132] According to a variant embodiment of the invention, the encryption key KE can be determined:

[0133] either through the server program associated to a processing and memorizing unit,

[0134] or through the server program using a remote auxiliary program and a processing and memorizing unit.

[0135] According to another variant embodiment of the invention, it can be planned to associate to each processing and memorizing unit:

[0136] at least one meter enabling to count accesses to restricted access resources, made by the user owning a processing and memorizing unit,

[0137] and a threshold for said meter.

[0138] Each server program for a service which receives a request of access to a restricted access resource, consults the values of the meter and threshold associated to the processing and memorizing unit used to send the request, so as to determine whether said request should be served or not. If the request is served, the server program possibly updates the meter's value.

[0139] According to a preferred variant embodiment of the invention, the meter is situated in a machine which centralizes the management of the metering of accesses to restricted access resources.

[0140] According to another variant embodiment of the invention, each process and memorizing unit comprises or includes:

[0141] a meter enabling to count the use of the decryption key KD,

[0142] and a threshold for said meter.

[0143] Such a meter is updated every time the decryption key KD is used and the decrypting of the encrypted responses received by the client program is forbidden when the meter reaches or exceeds the threshold. 

1- Process to restrict, to the benefit of authorized users, access to at least one resource belonging to at least one interactive service of at least one cluster of services, each user having a client machine (20) capable of executing a client program adapted to exchange from a transmission network (3), data with a server program associated to each interactive service which has a service identifier (S_(i)) (with i varying from 1 to I), access to a resource being provided by a request sent by the client program to the server program which processes said request and returns to the client program the response to the request, characterized in that it includes the following steps: for each cluster, putting at the disposal of each user, a processing and memorizing unit (30) designed to be linked up to the client machine (20) of the user when he wishes to access at least one restricted access resource, the processing and memorizing unit including: a cluster identifier (BU) enabling to determine the cluster to which the processing and memorizing unit belongs, a processing and memorizing unit identifier (UTM) enabling to characterize the processing and memorizing unit put at the user's disposal, and a decryption key (KD) enabling the decrypting of information coming from a service of the cluster, enabling each client program, to read in the processing and memorizing unit (30) which is linked up to it: the cluster identifier (BU), and the processing and memorizing unit identifier (UTM), sending by each server program for a service, at least once to any client program which has submitted a request to it for said service, a list of clusters identifiers (BS_(j)), (j varying from 1 to J) enabling to determine to which cluster(s) belongs the service to which the request was submitted, memorizing by each client program which receives a list of clusters identifiers (BS_(j)) in response to a request for a service having as service identifier (S_(i)), a relation between each cluster identifier (BS_(j)) and the identifier of the concerned service (S_(i)), determining, at the time of the sending of a request to a service which has a service identifier (S_(i)), if the client program has memorized at least one relation between a cluster identifier (BS_(j)) and the identifier of the concerned service (S_(i)), and in the case where: a cluster identifier (BS_(j)) is found, comparing said cluster identifier (BS_(j)) with the cluster identifier (BU) coming from the processing and memorizing unit and if they are equal, adding to the request sent by the client program, the processing and memorizing unit identifier (UTM), when a server program receives a request for a service containing a processing and memorizing unit identifier (UTM) and which requests to access a restricted access resource, determining by using at least the identifier of the concerned service (S_(i)) and the processing and memorizing unit identifier (UTM), if the user who owns the processing and memorizing unit is entitled to access said resource, and if the user: is not entitled to access the resource, returning to the client program by the server program, a response corresponding to a refused access, is entitled to access the resource: determining using at least the processing and memorizing unit identifier (UTM), the encryption key (KE) corresponding to the decryption key (KD) contained in the processing and memorizing unit linked up to the client machine of the user who has sent the request, encrypting by the server program, at least in part, the response to the request of access to the restricted access resource using the encryption key (KE), so as to obtain an encrypted response, and returning to the client program by the server program, said encrypted response, and when a client program receives an encrypted response: decrypting the encrypted response received by the client program using the decryption key (KD) contained in the processing and memorizing unit linked up to it, and presenting the user with the response to his request, as if said request had reached him non encrypted. 2- Process according to claim 1, characterized in that it comprises: determining, at the time of the sending of a request to a service, if the client program has memorized at least one relation between a cluster identifier (BS_(j)) and the identifier of the concerned service (S_(i)), and in the case where: several clusters identifiers (BS_(j)) are found, comparing said clusters identifiers (BS_(j)) with the cluster identifier (BU) coming from the processing and memorizing unit and if an equality is found, adding the cluster identifier (BU) to the request sent by the client program and already containing the processing and memorizing unit identifier (UTM), when a server program receives a request for a service containing a processing and memorizing unit identifier (UTM) and a cluster identifier (BU) and which requests to access a restricted access resource, determining by using at least the cluster identifier (BU), the identifier of the concerned service (S_(i)) and the processing and memorizing unit identifier (UTM) if the user who owns the processing and memorizing unit is entitled to access said resource, and if the user: is not entitled to access the resource, returning to the client program by the server program, a response corresponding to a refused access, is entitled to access the resource: determining using at least the cluster identifier (BU) and the processing and memorizing unit identifier (UTM), the encryption key (KE) corresponding to the decryption key (KD) contained in the processing and memorizing unit linked up to the client machine of the user who has sent the request, encrypting by the server program, at least in part, the response to the request of access to the restricted access resource using the encryption key (KE), so as to obtain an encrypted response, and returning to the client program by the server program, said encrypted response. 3- Process according to claims 1 or 2, characterized in that it comprises: enabling to link up simultaneously several processing and memorizing units (30 ₁), (with 1 varying from 1 to L), to the client machine of at least one user, enabling each client program to read in each of the processing and memorizing units which are linked up to it: the cluster identifier (BU₁), the processing and memorizing unit identifier (UTM₁), determining at the time of the sending of a request to a service having a service identifier (S_(i)), if the client program has memorized at least one relation between a cluster identifier (BS_(j)) and the concerned service identifier (S_(i)) and in the case where: a cluster identifier (BS_(j)) is found, comparing said cluster identifier (BS_(j)) with the clusters identifiers (BU₁) coming from the processing and memorizing units and if an equality is found, adding to the request sent by the client program, the processing and memorizing unit identifier (UTMI) having checked said equality, several clusters identifiers (BS_(j)) are found, comparing said clusters identifiers (BS_(j)) with the clusters identifiers (BU₁) coming from the processing and memorizing units and if at least one equality is found: choosing one of the processing and memorizing units having checked an equality, and adding to the request sent by the client program, the chosen processing and memorizing unit identifier (UTM₁) and the corresponding cluster identifier (BU₁), when a client program receives an encrypted response: finding the processing and memorizing unit whose identifier (UTM₁) has been transmitted during the request corresponding to said response, decrypting the encrypted response received by the client program using the decryption key (KD₁) contained in the processing and memorizing unit thus found. 4- Process according to claim 1 or 2, characterized in that it comprises determining whether or not the user is entitled to access a restricted access resource: either only through the server program, or through the server program using a remote auxiliary program. 5- Process according to claim 1 or 2, characterized in that it comprises determining the encryption key (KE): either only through the server program, or through the server program using a remote auxiliary program. 6- Process according to claim 5, characterized in that it comprises determining the encryption key (KE): either through the server program and a processing and memorizing unit, or through the server program using a remote auxiliary program and a processing and memorizing unit. 7- Process according to one of the claims 1 to 6, characterized in that it comprises: associating to each processing and memorizing unit: at least one meter enabling to count accesses to restricted access resources made by the user owning said processing and memorizing unit, a threshold for said meter, enabling each server program for a service, which receives a request of access to a restricted access resource: to consult the values of the meter and threshold associated to the processing and memorizing unit used to send the request, so as to determine whether said request should be served or not, and if the request is served, to possibly update the meter's value. 8- Process according to one of the claims 1 to 6, characterized in that it comprises: integrating to each processing and memorizing unit: a meter enabling to count the use of the decryption key (KD), a threshold for said meter, updating the meter every time the decryption key (KD) is used, and forbidding the decrypting of the encrypted responses received by the client program using the decryption key (KD), when the meter reaches or exceeds the threshold. 9- Processing and memorizing unit for the implementation of the process according to one of the claims 1 to 8, characterized in that it includes at least: a cluster identifier (BU) enabling to determine the cluster to which the processing and memorizing unit belongs, a processing and memorizing unit identifier (UTM) enabling to characterize the processing and memorizing unit put at the user's disposal, and a decryption key (KD) enabling the decrypting of information coming from a service of the cluster. 10- Processing and memorizing unit according to claim 9, characterized in that it includes: a meter enabling to count the use of the decryption key (KD), a threshold for said meter. 11- Client machine of the computer type, characterized in that it includes means to execute a client program implementing the steps of the process in accordance with one of the claims 1 to
 8. 12- Server machine of the data processing type, characterized in that it includes means to execute a server program implementing the steps of the process in accordance with one of the steps 1 to
 8. 13- Client program to access at least one restricted access resource belonging to at least one interactive service, comprising means programmed to carry out the steps of the process in accordance with one of the claims 1 to 8, when said client program is executed on a client machine (20). 14- Server program for interactive service comprising means programmed to carry out the steps of the process in accordance with one of the claims 1 to 8, when said server program is executed on a server machine (30). 